Cryptographer/Theoretical Computer Scientist Manoj Prabhakaran taught a course on expanders at the University of Illinois this Fall semester. Besides the links to other excellent courses on expanders, Manoj organized a course blog where students recapped various lectures. The part new to me: one of the course "requirements" was that students were encouraged to post articles to the "expanders" section of Wikipedia. While I don't see many articles on expanders that were ostensibly created by students of this course, I think this is a brilliant idea -- there's an important difference between transcribing course notes and writing Wikipedia articles. With your LaTeX hat on, you know you're writing for fellow "Doctorate in Expanders" diploma holders, but when you're writing Wikipedia articles, you have a hazier picture of your reader as a reasonably smart, somewhat scientific, citizen on the net (a good approximation is often a smart first-year graduate student). Good writing practice for graduate students. Way to go, Manoj.

Friday, December 16, 2005

It has happened again: another US professional sports team relocated, with all the usual griping about stadium/facilities, the usual cold business logic interfering with passionate fandom, everything. The scale is smaller -- Major League Soccer team San Jose Earthquakes are moving to Houston. Why? No one knows. The Quakes have a rich history in the Bay area, dating back at least 30 years (on and off, along with rise and fall of pro-soccer in the U.S.), have a strong fan base and ties to the community, etc.

Unfortunately, for its "owner/operator" Anschutz Entertainment Group (AEG), it wasn't enough. The deal they had with San Jose State University, whose Spartan Stadium the Quakes played in (and which was home to the first match of the MLS), wasn't sweet enough for AEG -- they didn't get as much of the revenue-sharing from parking/beverage-snack-sale, etc. as they wanted. No other local investor wanted to buy them (although some, notably due to the tireless efforts of SoccerSiliconValley, a grassroots organization, tried) unless a city-funded stadium proposal came through. Which, of course, didn't, since it would be a heavy tax-burden, probably wouldn't pass the voter-approval it requires, not to mention the fact that during the crucial discussion time the mayor of San Jose was embroiled in his own set of problems (a censure from the city council), etc.

The sad part is that no party got creative enough. Let's face it, soccer isn't as popular in the U.S. as (American) football and basketball and baseball are; if a team plays 15 home games with an average attendance of 12 to 15 thousand fans who buy tickets at an average price of (say) $20, it just isn't enough (since the other revenue --- merchandise, etc. isn't a whole lot more, either) for a pro-team to thrive. (Of course, none of this explains why moving to Houston would solve the problems.) It's sad that the direction MLS is heading, every team wants its own "soccer-specific stadium", and some have got it (the Home Depot Center shared by two L.A. teams, Chicago, NYC, Washington, DC, Columbus, Dallas..). I am guessing that when attendance is low (as happened this past season in Columbus, OH, with a team that sucked), the soccer-specific stadia are more of a money drain (to the community at large).

What does creative mean here? Any time there is an endeavor that a non-trivial but not terribly large number of people support (e.g., symphony, soccer, etc), this issue comes up again and again. In the present case, there is a large soccer fan base that is, unfortunately, spread quite a bit across Northern California; the Earthquakes could have played half their home games in Spartan and the other half somewhere north of the Golden Gate Bridge -- fewer games might have meant more-packed stadia, probably forcing SJSU to commit to better revenue-sharing. More fans would be able to watch the Quakes, broadening the Quakes fan base. As it turned out, the move to Houston only hurts all parties concerned -- Quakes fans lost their team, SJSU lost good revenue, AEG needs to rebuild a fan base in Houston (where it has similar stadium issues to deal with momentarily), players will be playing their matches at an average summer temperature of 90--95 deg. Farenheit.

Good luck to the Quakes players and coaches -- they were an amazing bunch, they worked their hearts out on the field and off the field (involvement in youth soccer, primarily). At least they are moving to a place that's more affordable with a United States pro-soccer player's salary.

Friday, December 09, 2005

Tulane University is eliminating its undergraduate programs in CS and EE, and laying off about 230 faculty members. I understand that it must have been a really difficult decision, but this quote makes me wonder:

"This is the most significant reinvention of a university in the United States in over a century," declared Scott Cowen, the university's president.

Reinvention? I thought that was a positive word.

Anyone who has been involved in recruiting at academic/research institutions will appreciate the pain of having, at some point, to find 230 highly-talented academics and convince them to join an institution.

Aren't there other solutions? Creative ones? It seems reasonable to believe that much of Tulane's budget comes from tuition and alumni donations, and I don't understand why that should suddenly vanish once the school is back in business. And students are inherently a floating population -- I don't know what fraction of Tulane's student body is heavily rooted to New Orleans.

Somehow this drastic step seems just wrong. In times of tragedy, art and science and craft and philosophy need to go on, and in fact, go on more vigorously.

Tuesday, December 06, 2005

The results for the Siemens Westinghouse Math, Science, and Technology competition for highschoolers are out -- Michael Viscardi, a home-schooled teenager from San Diego is the winner for his work on the Dirichlet problem. It's nice to see a teenager able to produce new mathematical work; I always find it disappointing that similar competitions, eg., the Intel contest, always produce lots of entries/winners in the "natural sciences" and rarely in mathematics. This years finalists also included an entry in "computer science", specifically related to the area of search -- cool.

On the other hand, since home-schooled children often enjoy a curriculum tailored to their individual pace of learning, should we consider Michael's "school age" closer to 20?

Incidentally, when I probed the Internet to read about what Dirichlet problems are, I was astounded to see an entry in the Wikipedia that already includes a mention of Viscardi's work. The power of the web...

Monday, November 21, 2005

Here's another attempt at separating NP from P, this time from the backwaters of beautiful Ernakulam in Kerala, India. The title says "NP != P and CO-NP != P", whence it follows that the proof is almost surely wrong. No self-respecting mathematician would've written the second part of the title.

(For the programming-languages-challenged, "!=" is the same as $\neq$)

Sunday, November 13, 2005

Pope Benedict XVI has waded into the evolution debate in the United States, saying the universe was made as an "intelligent project" and criticizing those who say its creation was without direction. .... He quoted St. Basil the Great as saying that some people, "fooled by the atheism that they carry inside of them, imagine a universe free of direction and order, as if at the mercy of chance."

Op-Ed: Our Faith in Science by Tenzin Gyatso, the 14th Dalai Lama.This is very interesting, for in the middle of an otherwise thoughtful, balanced and progressive article, the Dalai Lama slips in this scary sentence:

Yet the ramifications of [the progress in science, esp. genetic manipulation] are such that it is no longer adequate to say that the choice of what to do with this knowledge should be left in the hands of individuals.

One more alarmist article about how the U.S. might be losing its "competitive edge" in "innovation" -- worries ranging from how science is not emphasized enough in grade school to how Singapore and China grant more PhDs in science and engineering than the US.

I just don't get it. Why is it bad for the U.S. if the rest of the world makes significant advances in science and technology? On the contrary, I believe it is good for everyone, especially the U.S. As newer and newer innovations take place, they often tend to become interdependent -- a giant example is how personal computing, wireless communications, and the Internet are coming together in ways we might not have seen a decade ago. When these interdependencies grow, there will be significant opportunities for the U.S. both in terms of business deals and in terms of scientific exchange.

A case in point: India. While I was growing up as a teenager in India, there was much concern within India about "brain drain" -- about how a large number of the top students from Indian institutions routinely left for higher studies in the U.S., and how it was going to undermine India's investment in science and technology education. This notion seems almost silly today. A good deal of India's "modern economy" is built around the computing services sector, thanks in large part to being tuned in to the advances in computer science elsewhere (primarily the U.S.).

I hope the alarmists will shed their paranoia and instead celebrate the fact that more and more of the world is joining the culture of innovation and advanced science and technology. It just might be good for all of us.

I wonder why. Oxford Press' "Very Short Introduction" series has nearly 30 titles in the "Science" section, including such topics as "Philosophy of Science" and "Jung" and "Consciousness", but none on the science of computing. There's one on cryptography, but I am quite certain no two scientists who consider themselves cryptographers will agree on what ought to be in a book with that title :-). Absolutely nothing on the "Internet" or "Algorithms" or even "Artificial Intelligence", a favorite among the non-scientific audience. John Battelle's "Search" has made it to under-200 on the Amazon sales rank, but that's more of a meta-CS book (historical anecdotes, biographical stories, business wisdom, etc.) than an actual CS book.

Why isn't there a popular book talking about how some early computer scientists like Turing and von Neumann had tremendous foresight and got some basic "design decisions" right (like universal machine, stored program computer, etc.)? If there's a CS book for the masses, what, gentle reader, would you like to see in it?

Friday, October 28, 2005

Yesterday my sixth-grade son, doing his math homework, asked Is there a faster way to divide a number by another other than with long division? I had no good answer to that. Any suggestions for an alternative to tedious long divisions?

Here's a good alternative: not doing them.

A few years ago, I taught my then-six-year-old to do division, essentially by binary search. If you want to distribute 4832 cookies among 23 children, look at the sequence 23, 46, 92, 184, 368, 736, 1472, 2944, 5888, to figure out that each one will get at least 128, and you'll be left with 4832-2944 = 1888 cookies; of course, you can now give each one 64 more, using up 1472 and leaving you with 416, etc. (Of course, you will do this with powers of 10 if you are less of a sadist than I am). A year later, he probably forgot all about the mechanics of doing division, but still carried with him the ideas of division as distribution, perhaps the underlying "recursion", etc. Which is just as well.Tony Ralston (an ex-president of the ACM!) has a rather interesting take on the theme of paper-and-pencil arithmetic, where he advocates mental arithmetic and basic number sense.

Two excerpts (PPA = paper-and-pencil arithmetic):

So is a facility with PPA necessary - or even desirable - for later study of mathematics? If a student arrives in secondary school, say in a first algebra course, unable to do PPA, is that student ipso facto disadvantaged compared to students with PPA skills? I take it that it is not PPA skill itself which critics of calculator use consider important. After all, there is little secondary school or other mathematics which requires much computation per se. Rather it must be the ancillary benefits of developing PPA skill which are considered important. These are usually subsumed under the rubric of numeracy or number sense and include, in addition to the obvious ones of knowing the addition and multiplication tables, such things as knowing which arithmetic operation to use when, having a good sense of number size and knowing strategies to check the answers to arithmetic operations. These are all important. Is there anything about them which a calculator-based curriculum could not instill? I think the answer is, no...

and on long division:

I should say a word about division. Although it is over 15 years now since the Cockcroft Report [1982] recommended that long division no longer be taught in British schools, this recommendation been, at most, spottily implemented. The California Board of Education standards [California, 1998, p43] would require students to master long division. This is mind-boggling. The only excuse can be that those who promulgated the California standards believe that long division is good for the soul. Not only does being able to do long division have no practical value whatever but, in addition, the time required to teach this algorithm to students is far, far in excess of any benefit which might accrue from learning it. Of course, students must learn what division is, when to apply it, what remainders are and how to do simple division problems mentally. But teaching long division is pertinent to none of these aims; it is as nonsensical as teaching the square root algorithm which was staple fare until recent times. I cannot help but believe that those who favor teaching long division in elementary school (and these include some research mathematicians [Klein, 1998]) are in the grip of some fantasy about what is important and useful in school mathematics6

Wednesday, October 26, 2005

Lance Fortnow's blog entry Selling Theory raises several interesting issues, and I have three things to say about these.

Regarding the comment:

But [NYT's] Tuesday section Science Times has moved over the last couple of years from a general covering of science to a focus on medicine, environment and astronomy. Not just computer science but physics and chemistry get far less coverage than they once did.

One very important reason for this, in my opinion -- and I've often expressed this opinion in the past -- is that the latter fields (medicine, environment, astronomy) all have big goals that can be concretely stated so that an eighth grader can relate to them. "Cure cancer" or "300mpg cars", or "Flight to Mars" are all crisply stated, easy for a young mind to latch on to, and are more or less legitimate ambitions of the fields. Theoretical computer science, even Computer Science, lacks such ambitions. "Computers you could talk to" is about the best I can come up with that the median-quality high-schooler could understand. Perhaps something about doing functional genomics might appeal to smart undergraduates, but that's probably perceived more as a career in biology than in CS. Notice that physics, chemistry, etc. all have the same problem --- you could appeal to an eighth grader's imagination by talking about the expanding universe (or multiverse), but it's not tangible enough.

Lance writes

Computer science is a victim of its own success, by making computers powerful, easy to use and well-connected, we have turned computers into a commodity like cars with the mystique of computation and complexity lost on the users.

I don't think this is necessarily bad --- there are more users of automobiles than there are engineers working on building better ones, and even fewer scientists (or even "theoretical engineers") who think about the underlying laws of physics.

Finally, getting back to "selling theoretical computer science", I think we have a real problem. It's not so much that The New York Times doesn't write about what happens in TCS and why it is important. How many computer scientists that are not theorists appreciate the importance of theory? We need to do a much better job of convincing our colleagues in our departments, our graduate and undergraduate students that theoretical CS is not an arcane area of investigation, but a lively, vibrant area that, on the one hand, has deep philosophical and mathematical ramifications, and on the other hand, has real connections to the world around us. I think we simply cannot afford to have undergrad CS majors walk away with the feeling that this an anachronism in the day and age of the Internet (which they might if all they study are context-free languages and all-pairs-shortest-paths in the abstract form). The rest of CS has, in my opinion, done a better job in keeping up with their own growth. We don't seem to be offering any hint to the smart undergraduate that TCS is a constantly evolving discipline (just in the last ten years, we have had game theory, quantum computation, massive data set computations, etc. blossom from marginal curiosities into full-fledged multiple STOC/FOCS sessions). Jon Kleinberg's Information Networks, Michael Mitzenmacher's Algorithms at the end of the wire, the CMU course Algorithms in the real world, are all excellent examples of what we can do to improve the perception of TCS within computer science departments.

Thursday, September 22, 2005

Last night, India's finance minister P. Chidambaram was the guest on The Charlie Rose Show. He conducted a thoroughly riveting and very articulate hour-long conversation with Rose, in which he touched upon numerous topics -- ranging from the emergence of India and China as economic powerhouses, India's relationship with Pakistan, the importance of investing in infrastructure (and not just physical infrastructure), India's handling of the AIDS crisis, Iran's nuclear ambition, etc. What impressed me most was his ability to not stray off-topic and wander into self-promotion. He graciously mentioned that one of the reasons why he and Manmohan Singh were able to carry out various economic reforms in India was simply being at the right place at the right time.

Two aspects of the interview where I felt he could've fared better were:

(1) On discussing the question of outsourcing, he drew a distinction between "outsourcing of jobs" and "outsourcing of work", and claimed that what is happening is the latter, not the former. He went on to argue that India, in fact, outsources significantly to the U.S. in the areas of design, technology, etc. Absolutely true. He also pointed out to the significant investment opportunity in India that arises from infrastructure building. He seemed to imply (without ever saying so) that the task of converting profits from investments and selling of design and technology into jobs and well-being for the American masses is something that American businesses and Government need to figure out how best to address. That is a rather tricky problem, and personally, I don't think "trickle down" isn't going to cut it.

(2) To me, it seemed like he underplayed the importance of Gandhian economics (a very tight, but essentially very "local", network of farming and trading communities across the geo-social landscape of India) in keeping the country fairly stable through rather difficult global economic climate. While the U.S., Europe, and the richer Asian countries struggled massively during the economic downturn of 2001 (well before the September 11 attacks), India's economic base was solid, and this was not just because of any delays in ripple effect. In terms of going forward, I am concerned about his vision to translate massive investments, especially foreign direct investments, into the elimination of poverty -- he didn't seem to offer any clue about how that might happen (again, I am inferring that he is relying upon "trickle down"). That worries me. Trickle down has not proven to be a successful strategy in wealth distribution in a very large scale (where the number of "leaf nodes" is in the order of a billion).

To the vast majority of Indians who are poor, and clearly to the 30 percent who are below the poverty line, globalization means nothing so far. In fact, they want to be integrated with the Indian economy. They're outside the production processes here because they have no skills, they've no capital, they've no jobs, they've no property. They really have to be integrated with the Indian economy first. They have to be brought into the Indian production stream. To them globalization means nothing.